Oil burner safety shutoff switch



Nov. 9, 1954 A. GILETTO OIL BURNER SAFETY SHUTOFF SWITCH 2 Sheets-Sheet1 Filed Sept. 25, 1952 IN VENTOR. 4/7 L /70x79 Gf/e 1- f0 ATTUP FT SNov. 9, 1954 A. GILETTO OIL BURNER SAFETY SHUTOFF SWITCH 2 Sheets-Sheet2 Filed Sept. 25, 1952 m B m a Q INVENTOR. A/nhcmy Gi/ezzo ATTD RN EYEUnited States Patent OIL BURNER SAFETY SHUTOFF SWITCH Anthony Giletto,Philadelphia, Pa.

Application September 25, 1952, Serial No. 311,349

1 Claim. (Cl. 340-267) This invention relates to safety devices usedprimarily in combination with oil burners, and in particular a switchadapted to be installed on a stack or flue leading from a combustionchamber in which an oil burner is positioned with a plate extended intothe stack, hinged to the extended end of an arm and adapted to beactuated by an explosion in the combustion chamber for operating aswitch to open a circuit to a motor operating an oil burner and closinga circuit to a signal light indicating that the burner is inoperative.

The purpose of this invention is to prevent fire resulting fromexplosions in oil burner installations and to provide means fordisplaying a warning signal when such an explosion occurs.

In the conventional type of oil burner installation safety devices areprovided to prevent continuous flow of fuel when ignition fails or whenthe operation of the burner stops for other reasons, however, eventhough the fuel flow stops temporarily gases from accumulations of fuelin the burner housing cause explosions when an attempt is made to startthe burner or when the ignition system is actuated.

With this thought in mind this invention contemplates a switchpositioned on a stack or flue leading from a combustion chamber in whichparts thereof are mechanically connected to a door or baffle positionedin the stack or flue whereby with the door actuated by the force of anexplosion the circuit to an operating motor of an oil burner of theinstallation is broken.

The object of this invention is, therefore, to provide means for forminga warning device whereby the device is actuated by the force of anexplosion in a combustion chamber whereby a circuit to operating meansof an oil burner or the like is stopped by the force of the explosion.

Another object of the invention is to provide a safety device fordetecting an explosion in an oil burner installation in which the devicemay readily be installed on installations now in use.

A further object of the invention is to provide an explosion detectingand warning device particularly adapted for oil burner installations inwhich the device is of a simple and economical construction.

With these and other objects and advantages in view the inventionembodies a switch box having a warning light therein with means formounting the box on a stack or the like, and a rod extended from the boxthrough the connection of the box to the stack and into the stackwhereby the force of an explosion in the stack operates the switchthrough the rod.

Other features and advantages of the invention will appear from thefollowing description taken in connection with the drawings, wherein:

Figure 1 is a vertical section through the device showing the switch boxmounted on a stack, the stack also being shown in section, and thesection being taken on line 1-1 of Fig. 2.

Figure 2 is a sectional plan through the explosion actuated switch takenon line 2-2 of Fig. 1.

Figure 3 is a section, similar to that shown in Fig. 2, looking upwardlytoward the under side of the safety device.

Figure 4 is an elevational view looking toward the face of the switchbox of the safety device.

Figure 5 is a cross section through the switch box of the safety devicetaken on line 5-5 of Fig. 3.

Figure 6 is a cross section through the switch box tended from theswitch box into the stack through the door or battle, that operates thedevice.

Referring now to the drawings wherein like reference characters denotecorresponding parts the improved oil burner explosion safety device ofthis invention includes a switch box 10 connected by a sleeve 11 to astack 12 with a rod 13 journaled on supports 14 and 15 extended from thesleeve 11 and actuated by a door or baffle 16 through arms 17 and 18whereby as the door 16 is forced open by an explosion the rod 13 isrotated to turn a trigger 19 whereby the trigger actuates a rocker arm20 to disconnect contacts 21 and 22 at one end and connect contacts 23and 24 at the opposite end whereby a circuit 15 broken to a motor foractuating an oil burner and another circuit is completed to a .light 25which gives a warning indicating that an explosion has occurred.

The switch box 10 is carried by the sleeve 11 which is secured by a setscrew 26 in a flange 27 of a ring 28 and the end of the sleeve extendedthrough the rear wall 29 of the switch box is provided with a mountingflange 30 to which the operating parts of the switch are connected. Aninsulating bafile 31, spaced from the rear walls 29 of the switch boxprotect the box from heat of the stack.

The sleeve 11 is provided with a block 32, of insulating material andthe block is secured in the sleeve with a set screw 33. The bars 14 and15 are mounted in the block 32 and, as illustrated in Fig. 3 the bars 14and 15 extend from the block 32 and the extended ends are connected witha cross bar or piece 34. The door 16 is pivotally connected to the crossbar 34 with a hinge 35 and, as illustrated in Fig. l, the door 16 isadapted to be moved outwardly as shown by the dotted lines whereby thearms 17 and 18 rotate the rod 13. The arm 17 is pivotally connected tothe arm 18 with a pin 36 and as the door 16 is moved outwardly the arm18 draws the lower end of the arm 17 toward the opposite side of thesupport whereby the rod 13 is rotated.

As the rod 13 is rotated the trigger 19 moves the contact end 37 of therocker arm 20 away from the spring contacts 21 and 22 and in thismovement the opposite end 38 of the rocker arm moves into positionbetween the contacts 23 and 24, thereby completing a circuit to thelight 25. The rocker arm 20 is pivotally mounted by a pin 39 in abearing 40 and the extended edge of the arm is provided with a button 41by means of which the arm may be returned to the position shown in Fig.5. A spring 42, positioned between the rocker arm and a base 43 on whichthe contacts 21, 22, 23, and 24 are mounted, urges the rocker armoutwardly thereby assisting the trigger 19 in actuating the rocker armto break the circuit to the motor and close the circuit to the light.

The contacts at one side of the switch are. grounded by a wire 44 andthe circuit to the motor is completed by a wire 45 through a terminal 46and a contact bar 47 to the contact 22. The circuit to the light iscompleted by a wire 48 which is connected to the terminal 49 on thecontact 24.

The light bulb 25 is positioned in a socket 50, one terminal of which isgrounded, and the other connected to the wire 48 through a contact 51.

The switch box is provided with a door 52 having an opening 53 throughwhich the light 25 may be displayed and a knob 54 by which it may beopened and closed. The door is mounted on the switch box with hinges 55and 56. The switch box is provided with a plurality of ventilatingopenings 57.

The arm 18 is attached to the door 16 with a clip 58 and the clip 58 issecured to the door with a screw 59. The bar 14 is provided with abearing 60 in which the extended end of the rod 13 is journaled and theopposite end of the rod is journaled in the flange 30 on the end of thesleeve 11.

The switch box 10 is provided with an outlet nipple 3 61 through whichthe wires for the electrical connections extend.

Although the device is shown and described as providing a visible signalit is understood that the circuit completed by the rocker arm as aresult of an explosion may 1also sound an alarm or provide a suitableaudible signa.

It Will be understood that modifications, within the scope of theappended claim, may be made in the design and arrangement of the partsWithout departing from the spirit of the invention.

What isclaimed is:

In combination, a stack provided with an opening therein, a flangesurrounding said opening and secured to said stack, a sleeve projectingthrough said flange and into said stack, a switch box including a rearwall provided with an opening for receiving said sleeve, an insulatingbafile spaced from said rear Wall for protecting the switch box fromheat from the stack, a block of insulating material secured within saidsleeve, a pair of bars extending from said block, a crosspiece intercommeeting the free ends of said bars together, a door hingedly connectedto said crosspiece, a rod rotatably positioned in said stack, armspivotally connecting said rod to said door for rotating said rod uponpivotal movement of said door, a trigger actuated by said rod,

pivotally mounted in said bearing and having a button thereon, saidrocker arm abutting said trigger, a coil spring arranged in engagementwith said rocker arm, an indicating member positioned in said switchbox, a first pair of contacts connected to said indicating member andadapted to be engaged by an end of said rocker arm, and a second pair ofcontacts in said box -for connection to a motor and adapted to beengaged by the opposite end of said rocker arm.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 659,855 Meloon Oct. 16, 1900 989,132 Dewey Apr. 11, 19111,171,192 Haas Feb. 8, 1916 1,693,309 Mettler Nov. 27, 1928 2,013,225Waters Sept. 3, 1935' 2,244,373 Powers June 3, 1941 2,421,768 Voliazzoet al. June 10, 1947 2,646,476 Landry July 21, 1953- 1 2,659,334 FiedlerNov. 17,, 1953

